Tratamento de águas cinzas sintética para fins de reúso através de métodos eletroquímicos

Abstract

The electrochemical behaviour of Fe and Al cathodes and anodes in synthetic greywater solution was investigated using standard electrochemical techniques and water quality analysis methods. The efficiency of COD, turbidity and solids removal of the electrocoagulation and electroflotation method for greywater treatment was discussed on the basis of the electrochemical processes occurring in the electrolyzer unit cell. The anodic processes and ohmic drop were found to be main source of overpotentials determining the overall cell voltage and power consumption whereas the cathodic processes and the cathode material play minor roles in the electrolyzer behaviour. The unstable processes related to the active – passive transition of surface film during the anode dissolution determine the balance between coagulant inflow and solids removal by electroflotation thus directly affecting the efficiency of the electrochemical treatment of greywater. The correlation between electrochemical behaviour of the anodes and the characteristics of the recycled greywater allowed us to obtain further insight into the electrocoagulation and electroflotation processes applied to wastewater treatment.